fix: UseSentry now initializes Sentry even when Logging.AddSentry ran first

The logging integration registers a non-initializing Func<IHub>, and the
initializing one was registered with TryAdd, so whichever ran first won. Calling
builder.Logging.AddSentry() before UseSentry therefore left the SDK disabled with
no indication, where v6 failed loudly at startup with "You must supply a DSN".

The initializing registration now replaces any existing accessor, so the order of
the two calls no longer matters. Tests cover both orders; the AddSentry-first one
fails without this change.

Calling both is still redundant and still registers two pairs of logger
providers, which is unchanged from v6.

Reported by Cursor Bugbot on #5595.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: jamescrosswell

src/Sentry.Extensions.Logging/Extensions/DependencyInjection/ServiceCollectionExtensions.cs

@@ -29,7 +29,10 @@ internal static IServiceCollection AddSentry<TOptions>(this IServiceCollection s
 
         if (initializeSdk)
         {
-            services.TryAddSingleton<Func<IHub>>(c =>
+            // Replaces rather than TryAdd: the logging integration registers a non-initializing accessor, and
+            // whichever is registered first would otherwise win. Initializing has to take precedence.
+            services.RemoveAll<Func<IHub>>();
+            services.AddSingleton<Func<IHub>>(c =>
             {
                 var options = c.GetRequiredService<IOptions<TOptions>>().Value;
                 var hub = SentrySdk.InitHub(options);

test/Sentry.AspNetCore.Tests/UseSentryWithLoggingAddSentryTests.cs

@@ -0,0 +1,49 @@
+#if NET6_0_OR_GREATER
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+
+namespace Sentry.AspNetCore.Tests;
+
+// Calling both UseSentry and Logging.AddSentry is redundant, but reachable. Whichever registered the hub
+// accessor first used to win, so calling AddSentry first left the SDK disabled.
+[Collection(nameof(SentrySdkCollection))]
+public class UseSentryWithLoggingAddSentryTests : IDisposable
+{
+    public void Dispose() => SentrySdk.Close();
+
+    private static IHub BuildHub(bool useSentryFirst)
+    {
+        var builder = WebApplication.CreateBuilder();
+
+        void UseSentry() => builder.WebHost.UseSentry((SentryAspNetCoreOptions options) =>
+        {
+            options.Dsn = ValidDsn;
+            options.BackgroundWorker = Substitute.For<IBackgroundWorker>();
+            options.AutoSessionTracking = false;
+            options.InitNativeSdks = false;
+        });
+
+        if (useSentryFirst)
+        {
+            UseSentry();
+            builder.Logging.AddSentry();
+        }
+        else
+        {
+            builder.Logging.AddSentry();
+            UseSentry();
+        }
+
+        using var app = builder.Build();
+        return app.Services.GetRequiredService<IHub>();
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void UseSentry_WithLoggingAddSentry_InitializesSdk(bool useSentryFirst)
+        => Assert.True(BuildHub(useSentryFirst).IsEnabled);
+}
+#endif